The sheriff remained mum on most of the details surrounding the fight, but told CNN that both Hernandez and the other guy were supposed to be in isolation. The other guy won’t be charged, and neither was seriously hurt. The sheriff told CNN last month that jail officials will investigate how the two inmates came into contact, because “no more than one inmate is supposed to be out at a time” in the unit where Hernandez is housed.

Even those small details are interesting given the circumstances under which Hernandez is kept in isolation. Solitary confinement is a controversial issue in Massachusetts, where legislators recently worked to limit its use in the state. This summer, Hodgson¬†told TMZ¬†that authorities had put the former Patriots tight end into isolation for his own protection. ‚ÄúWe wouldn‚Äôt want some inmate trying to get any notoriety by attempting to harm Aaron Hernandez,‚ÄĚ Hodgson said.

It’s common to justify solitary confinement with arguments that its for the safety of the prisoner, especially when he has notoriety, but it’s a justification that the ACLU rejected when they protested Hernandez’s isolation last summer:

Prison officials sometimes justify solitary confinement as necessary to separate vulnerable prisoners, such as¬†juveniles¬†and the elderly, or high-profile prisoners, like Hernandez, from the general population.¬†But this ‚Äúprotection‚ÄĚ comes at an unnecessarily high cost.

The ACLU points to studies that have shown the psychological harm solitary confinement can have. (It surely doesn’t seem to be¬†improving¬†whatever inclination toward violence Hernandez might have had when he entered prison.)

That misdemeanor charge doesn’t help, but it is, of course, the least of Hernandez’s legal troubles. In addition to the first-degree murder charge in the killing of Odin Lloyd, Hernandez is the target of an investigation into another double murder, and the subject of several civil suits.